Pit long adjusting device and optical disk origin board exposure device and optical disk drive device

摘要

PROBLEM TO BE SOLVED: To simply form a pit where a regenerative waveform of a recorded pit is adjusted to an optimum length by individually adjusting front edge part and rear edge part of a recorded pulse without changing a recording position. ;SOLUTION: A first pulse Pi is obtained by delaying a prescribed pulse P with a first delay circuit 1 of a delay amount of an integer number (n) ×minimum resolution At, and a second pulse P2 is obtained by delaying the pulse P with a second delay circuit 2 of the delay amount of a reciprocal T of a recording frequency + the integer number (m) ×Δt. Then, a third pulse P3 is generated by ADNDing both pulses with an AND circuit 3, and a fourth pulse P4 is generated by ORing both pulses with an OR circuit 4. Since the third, fourth pulses P3, P4 are pulse width corrected for a zero pulse PO delayed by the reciprocal T from the prescribed pulse P, pit length correction becomes possible without changing a pit central position even when a correction value is changed for a continuous pit. Thus, the third pulse P3 of a short pulse width for a high sensitive optical disk, and the fourth pulse P4 of a long pulse width for a low sensitive optical disk are inputted, and the length of the pit is adjusted.;COPYRIGHT: (C)1999,JPO